A fairly common OCS font from prerevolutionary editions of the 18th and 20th centuries.
There is a fairly well-known commercial font Psaltyr, reproduced from the same printed samples as Kathisma. The differences are few: the letters Kathisma are slightly wider, but the letter spacing is smaller; some letters are drawn differently; Carefully worked out kerning. I (Vladislav Dorosh) will not hide that the main goal of developing from scratch a font similar to the one already available is to create a free, non-commercial version that reproduces a pretty beautiful pre-revolutionary headset.